# 23.py
# 描述器

class Person():
  def __init__(self):
    self.__age = 10

  def get_age(self):
    return self.__age

  def set_age(self, value):
    if value <0:
      value = 0
    self.__age = value

  def del_age(self):
    del self.__age

  age = property(get_age, set_age, del_age)

p = Person()
print(p.age)
p.age = -1
print(p.age)
def p.age
# print(p.age)



